Electronic device with EMI screen &amp; packing process thereof

ABSTRACT

An electronic device with EMI screen and packaging process thereof to provide even active EMI prevention means includes adhesion of a transit substrate to a. soldering surface of the electronic device, a protection circuit layer functioning as EMI screen being paved on the bottom of the transit substrate; a packaging circuit layer being laid; protection circuit layer and the transit substrate as well as the packaging and protection circuit layers being segregated with an insulation material; and solder balls provided with electric continuity to the protection circuit layer and the packaging circuit layer being respectively implanted as soldering points respectively for EMI grounding and linkage between the electronic device and a printed circuit.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention is related to a packaging technology of electronic device, and more particularly to an electronic device provided with electro magnetic interference(EMI) protection circuit and packaging technology thereof.

(b) Description of the Prior Art

In a design of digital circuitry, conduction wire and circuit board radiate electromagnetic waves to affect layout of circuitry and wire in the perimeter of the circuit and any conductor that may transmit these electro magnetic (EM) waves, a phenomenon known as EMI. So far there is no way to absolutely exclude EMI; but hazards from EMI may be minimized by good circuit design and wiring technique for the circuit board.

For example, grounding, screening, and filtering methods may be employed to complete EM compatibility design. Wherein, the grounding method involves leading interference signals into a grounding end; screening, a screen material to resist EMI; and filtering, an EMI filter to stop interference signals.

All these three EMI preventive methods are the most common practices used for all electronic devices to prevent EMI. However, angling at the electronic device (electric installation), the means to prevent EMI is comparatively passive since its EMI preventive strategy must rely upon its EMI protection mechanism. Furthermore, EMI is essentially originated from excessive distribution density of electronic devices or from HF circuit. As the development of electronic products is heading for HF and smaller size; whether an electronic product is provided with sufficient space to build EMI protection mechanism justifies further discussion.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provide an electronic device provided with an EMI protection circuit and packaging technique thereof thus to give the electronic device a more active means to prevent EMI while favoring the development of the electronic device applied products in heading for HF and smaller size.

To achieve the purpose, a transit substrate is adhered to a soldering surface of the electronic device; a protection circuit layer functioning as an EMI screen is paved on the bottom of the transit substrate; a packaging circuit layer is laid; at where between the protection circuit layer and the transit substrate as well as where between the packaging circuit layer and the protection circuit layer are respectively segregated with an insulation material; and finally a solder ball with continuity to the packaging circuit layer is planted at a pre-designated location on the bottom of the transit substrate to serve as a soldering point to connect the electronic device and a printed circuit board thus to complete for the electronic device an even more active means to prevent EMI.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an electronic device of the present invention.

FIG. 2 is a schematic view showing a process of adhesion of a transit substrate in the present invention.

FIG. 3 is a schematic view showing a process of creating a primary insulation material in the present invention.

FIG. 4 is a schematic view showing a process of building up a packaging circuit layer in the present invention.

FIG. 5 is a schematic view showing a process of creating a secondary insulation material in the present invention.

FIG. 6 is a schematic view showing a process of cutting edge of the packaging circuit layer in the present invention.

FIG. 7 is a schematic view showing a process of building up a protection circuit layer in the present invention.

FIG. 8 is a schematic view showing a metallization process in the present invention.

FIGS. 9, 10, and 11 are schematic views showing a process of segregation on the margins of devices in the present invention.

FIG. 12 is a schematic view showing a process of implantation of solder ball in the present invention.

FIG. 13 is a schematic view showing a cutting of molding in the present invention.

FIG. 14 is a schematic view showing an evaporation process of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 for a basic configuration of an electronic device provided with EMI screen and its packaging process of the present invention, an electronic device 10 comprised of a wafer 12 and associate packaging unit 11 is the principal part of operating and is built on a substrate 14 (e.g., an insulation substrate) with an insulation plastic material 13; a transit substrate 15 is adhered to a soldering surface in opposite to the substrate 14 of the electronic device 10; a protection circuit layer 162 serving as an EMI screen is paved on the bottom of the transit substrate 15; a packaging circuit layer 161 is provided; and at where between the protection circuit layer 162 and the transit substrate 15 as well as where between the packaging circuit layer 161 and the protection circuit layer 162 are respectively segregated by means of an insulation material 17. A solder ball 192 provided with electric continuity with the protection circuit layer 162 to serve as a soldering point for EMI grounding and a solder ball 191 provided with electric continuity to the packaging circuit layer 161 serving as soldering point for connection between the electronic device 10 and a printed circuit board are implanted on pre-designated locations on the bottom of the transit substrate 15. Accordingly, the electronic device provided with an EMI protection circuit is given a more active means to prevent EMI while facilitating the development of an electronic product adapted with the electronic device 10 to head for HF and smaller size.

FIGS. 2 through 13 illustrate a packaging process for the electronic device 10 including steps involving adhesion of transit substrate, primary insulation material construction, packaging circuit layer construction, secondary insulation material construction, packaging circuit margin cutting, protection circuit layer construction, metallization, device margin segregation, implantation of solder ball, cutting into mold, and evaporation in sequence.

As illustrated in FIG. 2 for the process of adhesion of transit substrate, the transit substrate 15 is adhered to a soldering surface in opposite to the substrate 14; multiple electronic devices 10 are provided on the same substrate 14 to facilitate synchronous processing on those electronic devices 10.

The insulation material 17 related to a photo resist or epoxy is applied on the bottom of the transit substrate 15 and properly flattened to complete construction of the primary insulation material in a step as illustrated in FIG. 3.

A step of construction of packaging circuit layer as illustrated in FIG. 4 requires coating of a course on the insulation material 17 serving as the metal material for the packaging circuit layer 161.

As illustrated in FIG. 5, a step of secondary insulation material has the insulation material 17 related to the same photo resist or epoxy to be applied on the bottom of the packaging circuit layer 161 to become a passage 163 for providing electric continuity between the packaging circuit layer 161 and a solder ball through exposure and development processes.

In a step of margin cutting of the packaging circuit layer as illustrated in FIG. 6, those portions of the transit substrate 15 and the insulation material 17 connecting to each electronic device 10 are removed to expose margin of the packaging circuit layer 161 of each electronic device 10; if and when required, the margin of the packaging circuit layer 161 may serve the passage to connect each electronic device 10; and this step is omitted when only one electronic device 10 is packaged.

FIG. 7 shows a step for construction of protection circuit layer 162, an operation circuit for the electronic device 10 is laid on the secondary insulation material 17 to provide the protection circuit layer 162 with the passage 163 for the protection circuit layer 162 to achieve electric continuity with the solder ball; and the protection circuit layer 162 maybe linked to the packaging circuit layer 161 by means of the margin of the packaging circuit layer 161.

The packaging circuit layer 161, the protection circuit layer 162, and the passage 163 are metallized 181 in a step of metallization as illustrated in FIG. 8.

As illustrated in FIGS. 9 and 10 for a step to segregate margin of device, a solder mask 182 is applied to margin of each electronic device so to mask a portion of the circuit layer exposed for metallization as illustrated in FIG. 9; a portion of each electronic 10 to connect the substrate 14 is provided with a cutting line as illustrated in FIG. 10; and a glue material 183 is then filled into the grain as illustrated in FIG. 11 to prevent seepage of foreign materials into the electronic device 10. This step is skipped when only one electronic device 10 is packaged.

Now referring to FIG. 12 for implantation of solder ball, a solder ball 192 provided with electric continuity to the protection circuit layer 162 serving as a soldering point for EMI grounding, and another solder ball 191 provided with electric continuity to the packaging circuit layer 161 serving as a soldering point to connect the electronic device 10 and the printed circuit board are implanted on pre-designated locations on the bottom of the transit substrate 15 of the electronic device 10.

Finally, each electronic device 10 becomes an integrated device by cutting any portion of the substrate 14 that connects any two abutted electronic devices 10 as illustrated in FIG. 13 for a mold cutting step. This step may be omitted if the electronic device 10 is packaged alone.

Furthermore, an evaporation step as illustrated in FIG. 14 may be provided as an auxiliary process to upgrade EMI prevention performance by soldering tine or copper to the soldering surface of the electronic device 10 that is sufficient to lead out excessive current to reinforce EMI preventive efficacy of the electronic device 10.

The prevent invention provides an electronic device with EMI protection circuit and packaging technology thereof for giving an even more active means to prevent EMI thus to facilitate development of the electronic device applied electronic products to head for HF and smaller size, and this patent application is duly filed accordingly. However, it is to be noted that the preferred embodiments disclosed in the specification and the accompanying drawings are not limiting the present invention; and that any construction, installation, or characteristics that is same or similar to that of the present invention should fall within the scope of the purposes and claims of the present invention. 

1. An electronic device includes a transit substrate adhered to a soldering surface of the electronic device, a protection circuit layer serving as EMI screen being paved and a packaging circuit layer being laid on the bottom of the transit substrate; an insulation material disposed between the protection circuit layer and the transit substrate as well as between the packaging circuit layer and the protection circuit layer to segregate among the transit substrate, the protection circuit layer, and the packaging circuit layer; multiple solder balls with certain portion disposed on pre-designated location on the bottom of the transit substrate to maintain electric continuity with the protection circuit layer and serve a soldering point for EMI grounding, and other portion of those solder balls serving electric continuity with the packaging circuit layer and a soldering point to connect the electronic device to a printed circuit board.
 2. The electronic device as claimed in claim 1, wherein the electronic device has a wafer and associate packaging unit as a principal part of operation and is constructed on a substrate through an insulation material.
 3. The electronic device as claimed in claim 2, wherein the substrate is related to an insulation substrate.
 4. The electronic device as claimed in claim 2, wherein the insulation material relates to a photo resist or epoxy.
 5. An electronic device packaging process is comprised of the following steps: a. Adhesion of transit substrate, a transit substrate is adhered to a soldering surface of the electronic device; b. Primary construction of insulation material, an insulation material is applied on the bottom of the transit substrate, and properly flattened; c. Construction of packaging circuit layer, a course of metallic material as the packaging circuit layer is applied on the bottom of the primary insulation material; d. Secondary construction of insulation material, the insulation material is applied on the bottom of the packaging circuit layer to serve as a passage for providing electric continuity between the packaging circuit layer and the solder ball; e. Construction of protection circuit layer, a circuit is laid for the operation of the electronic device on the bottom of the secondary insulation material to form the protection circuit layer; and f. Implantation of solder ball, a solder ball serving as a soldering point for EMI grounding and provided with electric continuity to the protection circuit layer and another solder ball provided with electric continuity to the packaging circuit layer serving a soldering point to link the electronic device to a printed circuit board are implanted on pre-designated locations on the bottom of the transit substrate of the electronic device.
 6. The electronic device packaging process as claimed in claim 5, wherein an evaporation step is performed to coat solder ball, copper or the equivalent to lead out excessive material for reinforcing EMI prevention efficacy for the electronic device following the completion of implanting the solder balls.
 7. The electronic device packaging process as claimed in claim 5, wherein multiple electronic devices are constructed on the same substrate; the step of construction of the protection circuit layer for the electronic device is followed by a step of metallization for the protection circuit layer and the packaging circuit layer; a course of segregation for the margin of the device is provided to mask the metallized circuit by applying solder mask, to the margin of each electronic device; a cutting line is provided at where a portion of substrate connecting one electronic device to another; a plastic material is filled in the grain to prevent seepage of other materials into the electronic device; a course of molding cut is provided upon completing implantation of solder balls to the electronic device to cut off the portion of the substrate that connects any two abutted electronic devices to make each electronic device an integrated part.
 8. The electronic device packaging process as claimed in claim 7, wherein a margin cutting step is provided before the completion of the construction of the protection circuit layer for the electronic device; any portion of the transit substrate and insulation material connecting between any two abutted electronic devices are removed to expose the margin of the packaging circuit layer of each electronic device; and the margin of the packaging circuit layer becomes a passage to link both of the packaging circuit layer and the protection circuit layer to each other if and when required.
 9. The electronic device packaging process as claimed in claim 5, wherein the margin of the packaging circuit layer constitutes linkage between the packaging circuit layer and the protection circuit layer in the step of construction of the protection circuit layer.
 10. The electronic device packaging process as claimed in claim 5, wherein the insulation material used in the primary and the secondary constructions is related to a photo resist or epoxy.
 11. The electronic device packaging process as claimed in claim 6, wherein multiple electronic devices are constructed on the same substrate; a metallization step is provided on where both of the protection circuit layer and the packaging circuit layer are located following the completion of the construction of the protection circuit layer for the electronic device; a course of device margin segregation is followed by applying solder mask to the margin of each electronic device to mask the margin of each electronic device exposed to receive metallization of circuit layer; a grain is cut on the portion of the substrate connecting to each electronic device; a plastic material is filled in the grain to prevent seepage of other materials into the electronic device; course of molding cut is provided upon completing implantation of solder balls to the electronic device to cut off the portion of the substrate that connects any two abutted electronic devices to make each electronic device an integrated part.
 12. The electronic device packaging process as claimed in claim 11, wherein a margin cutting step is provided before the construction of the protection circuit layer to remove portions of the transit substrate and insulation material found between any two abutted electronic devices; margin of the packaging circuit layer of each electronic device being exposed; and the margin of the packaging circuit layer serving as a passage to link between the packaging circuit layer and the protection circuit layer.
 13. The electronic device packaging process as claimed in claim 6, wherein margin of the packaging circuit layer connects between the packaging circuit layer and the protection circuit layer in the step of construction of the protection circuit layer.
 14. The electronic device packaging process as claimed in claim 6, wherein the insulation material used in the primary and the secondary constructions is related to a photo resist or epoxy. 